Large-scale Grounding Grid Resistance Tester

Answer:
The instrument's core anti-interference technology utilizes frequency conversion, combined with high-end digital filtering technology and a DSP high-speed processor, fundamentally resolving strong electric field interference issues. Specific anti-interference designs include:
Built-in frequency conversion power modules generate test currents at non-standard frequencies (e.g., 45Hz, 55Hz), bypassing 50Hz power frequency interference. This precisely extracts target frequency signals while completely eliminating interference from power frequency, harmonics, high frequencies, and DC components.
Even in harsh electromagnetic environments of operational substations, with interference voltages up to 10V at the voltage leads and interference currents up to 1A at the current leads, measurement data remains accurate, stable, and highly repeatable;
Effectively eliminates mutual inductance effects between current and voltage lines in parallel wiring configurations, maintaining high measurement accuracy even when parallel wiring is adopted due to site constraints.

Answer:
I. Core Measurement Functions
Includes five core parameters: ground grid impedance, contact potential, step voltage, soil resistivity, and potential gradient. It can also simultaneously measure the pure resistive component R and pure inductive component X of the ground grid, meeting the assessment needs for large and medium-sized grounding grids.
II. Precautions for Contact Potential Measurement
Wiring Requirements: Current terminal C1 connects to the auxiliary current electrode; C2 connects to a designated structure point at least 1.8m above ground. Voltage terminal P1 connects to the structure at 1.8m; P2 connects to the grounding grid's metallic material at 0.8m from the structure.
Resistance Configuration: The instrument internally incorporates a 1500Ω resistor, eliminating the need for external parallel connection (compliant with national standards for this parameter measurement).
Data Calculation: The instrument displays the potential difference at 1A current. Actual contact potential must be derived by integrating the substation short-circuit current calculation value.
Safety Specifications: Before testing, ensure the instrument's ground terminal is reliably grounded nearby. Avoid touching terminals C1 and C2 during testing (maximum output voltage 100V).

Answer:
I. Data Storage and Export Methods
Built-in Storage: Equipped with a large-capacity memory and calendar chip, it can store 100 sets of measurement data in chronological order, supporting historical record queries and direct print output;
USB Export: Insert a USB drive into the panel USB port to export all data as date-named text files. Exported data can be viewed, managed, and reported on a PC using the accompanying software.
II. Data Security Measures
Export Restriction: Never remove the USB drive during data transfer to prevent transmission errors or drive damage.
Auto-Save: Core measurements like earth grid impedance and contact potential are automatically saved upon completion, eliminating manual intervention and preventing data loss.
Hardware Protection: The full-touch LCD display is a precision component. Avoid direct sunlight, heavy pressure, or sharp object scratches. Use a plastic stylus during operation to ensure accuracy and device stability.